In the past, much time, effort, and other valuable resources, have been expended in the development of animal litter, particularly for household pets, and especially cats. A material most widely utilized in animal litter is generally clay.
Clay particles provide small animals with dry, sanitary, dustless and relatively odorless litter. Through formational mismatching and distortion between the tetrahedral layers and impurities, diverse morphological and chemical properties are conferred to the clay. The absorption of liquid, particularly water, is one such phenomenon. The irregular series of layers with corresponding interstitial space comprise pores. It is those spaces and pores which give clay its capacity to absorb and store water or liquid waste. Sodium bentonite, a swelling clay, is a clay that naturally forms clumps around wetted litter to permit easy and selective removal. Clumps of wetted litter permit easy and selective removal of odor-producing liquid animal wastes for convenient disposal without having to replace the entire litter bed. Despite this advantage, sodium bentonite brings with it many disadvantages, chief among them that sodium bentonite is not optimal for odor control, the product is heavy, found primarily in Wyoming and thus is geographically undesirable, and can clog pipes if introduced into a typical residential plumbing system.
At least partly to match the convenience of sodium bentonite but to avoid various downsides of the ingredient, clumping agents have been devised which, when added to a bed containing non-swelling particles, cause the particles to clump together into an agglomeration of sufficient size and strength to be removed by a sieving spoon. Some prior art clumping agents include inorganic salts, such as anhydrous sodium sulfate, gypsum and the like, but these materials do not naturally degrade, can form insoluble hard water salts in household waste systems and thus are environmentally unacceptable.
Other clumping agents used in the prior art include water-soluble gums, dry particulate cellulosic ethers and water-absorbent polymers. However, these additives require careful handling during manufacture, multiple processing steps and are costly. Further, in such animal litter, the dry particulate cellulosic ethers or the water-absorbent polymers tend to segregate from the particulate clay during handling and shipping.
There is a need in the art for improved clumping agents.
Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.